SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '138d10ed7bc563d1a07f1ffde068a9a202321e6940b39da19cfae73709c5a5e2' 
  AND token = 'Kf18CugkD/IJ1GcZCfrkLesiKWBTmBBYW5WeoEKSx08=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}